Significant Accounting Policies (Tables)
 3 Months Ended
Mar. 31, 2012
Significant Accounting Policies [Abstract]  
Estimated Useful Lives Of Assets
Leasehold interests
Remaining lease term
Buildings and improvements
5 to 40 years
Tenant improvements
The shorter of the term of the
related lease or useful life
Furniture, fixtures and equipment
5 to 10 years